Twin hydraulic jack assembly



Nov. 22, 1955 L. c. WEINBERG TWIN HYDRAULIC JACK ASSEMBLY 2 Sheets-Sheet1 Filed July 31, 1951 INVENTOR. Lowell C. Wbinber ATTORNEYS Nov. 22,1955 1.. c. WEINBERG 2,724,572

TWIN HYDRAULIC JACK ASSEMBLY Filed July 31, 1951 2 Sheets-Sheet 2 J l oJ O J WM k G I I K J C v IlllllH H L 1 l -a T. J' l S o J O 2 b 2INVENTOR. i ifili1i* Lowell C.%imber United States Patent TWIN HYDRAULICJACK ASSEMBLY Lowell C. Weinberg Redondo Beach, Calif. Application July31, 1951, Serial No. 239,604

6 Claims. (Cl. 254-89) (Granted under Title 35, U. S. Code (1952), see.266) The present invention relates generally to hydraulic jacks andspecifically to a twin hydraulic jack for use with wheels and tires ofaircraft.

In the servicing of aircraft in hangars or on flight decks extremedifliculty has attended the replacement of wheels or tires due to thecompact construction of wheel hubs and axles used with retractablelanding gear. The hubs and axles are necessarily set close to the rim ofthe wheels and with the large size tires now in use on aircraft it hasbeen found diflicult to locate a vertically lifting device beneath theaxle stub. The large size tires when partially or totally deflatedspread out beneath the wheel to a degree which prohibits the use of ahydraulic jack beneath the jacking point on the hub or axle.

The present invention has for its object to provide a hydraulic liftingdevice which permits vertical lift of an aircraft wheel despite thecollapsed and spreadout tire carcass.

Another object of the invention is to provide a. hy draulic jack havingan extremely low compressed height and a high-extended height.

A further object of the invention is to provide a hydraulic jack that isreadily portable and has wheels which without adjusting or latching toinoperative posi tion do not bear any of the lift load while the jack isin position.

A further object of the invention is to provide a hydraulic jack ofinexpensive construction and one capable of lifting large loads as foundaboard aircraft carriers.

These and other objects of the invention will be more clearly understoodby reference to the accompanying description and drawings in which:

.Fig. 1 shows a partially exploded plan view of the invention.

Fig. 2 shows a cross-sectional view taken on line 2-2 of Fig. 3.

Fig. 3 shows a top plan view, and' Fig. 4 shows a side view inelevation'of the assembled invention.

Referring more particularly to the drawing in which like numeralsindicate like parts throughout the several views, in Fig. 1, will beseen a pair of hydraulic jacks having bases 11 securedto bar 12 by anglebrackets 13 and 14 (as seen in Fig. 4) at each end of bar 12. Brackets15 and 16 on bar 12 support a pump 17 which is connected at its outletend 18 with the distributing valve 19 and at its input end 21 to the oilreservoir 22 by pipe 23. The distributing valve 19 is connected byconduits 24 and 25 to each of the bases 11 by means of connectorsindicated at 20.

Bolted to bases 11 are brackets 26 having axles 27 and wheels 28rotatable thereon.

The hydraulic jacks 10, as shown in Fig. 2, are constructed of outersleeves 30 screw threaded into the bases 11, inner sleeves 31, andpistons 32, and are extended slidably together by fluid pumped intochambers 33 in the bases 11. As shown in the partially exploded 7 viewin Fig. 1 and also in the cross-section view of Fig.

2, the assembled sleeves 30, 31, and pistons 32 of each jack fit looselyinto the caps 35 at each end of the beam 36.

Caps 35 are cylindrical in shape and have their inner ends 37 concave tomatch and to provide a continuous bearing surface for the convex ends 38of pistons 32 under conditions of flexing of beam 36 or while one jack33 in the bases 11. As shown in the partially exploded is extendedslightly higher than the other.

Slidable on beam 36 are two riders 39 and 40, each having dependingflanges 41 to prevent them from sliding sideways from beam 36. Rider 39is a relatively low plate with a hole 42 into which fits pin 43 formedin the base of the load cup 44. Other load cups 45, 46, with identicalpins 43, are of diiferent thicknesses and are replaceable with cup 44 inrider 39 or may be used with rider 40 in the hole 48 on top of theadjusting screw 47. Beam 36 has hole 49 at its center for receiving oneof pins 43 when one of the cups 44, 45, or 46 are used to bear theweight of the lifted load without the increment of height added by theuse of either rider39 or 40.

Each of the riders 39 and 40 have identical springbased centering pins51 having the pull-handles 52, the pin 51 of the rider chosen for usecoacting with hole 53 in beam 36 to fix the rider in the center of thebeam. Load cups 44, 45, 46 have short cables 54 securing them againstloss or misplacement.

The purpose of riders 39 and 4t) and load cups 44, 45 and 46 is toprovide means for contacting and bearing the lifted load at minimum jacktravel regardless of the height of the lifting points of the load fromground level. The height of the lifting point will determine whichbearing means is to be used in order that the full vertical jack travelremains and is present to lift the load the required distance. At thelowest lifting point, hole 49 and its load cup is utilized; at anintermediateheight rider 39 is used, and at higher lifting points, rider40 with its adjusting screw 47 is used. Load cups 44., 45 and 46 areinterchangeable with each other in holes 42, 48, and 49 and havedifferent sized depressions 63 to fit different sized loading points.

In operation, the oil return valve 60 is closed and distributing valvehandle 61 is centered to obtain equal flow from pump 17 to each jack 10,and air vent 62 in the top of the reservoir 22 is opened to replenishthe oil in pump 17 as it fills the jacks. If one jack lil raises fasterthan the other or if it is desirable to have one jack higher than theother to accommodate slight irregularities in the deck surface, handle61 is moved towards the jack requiring the more oil, the particularconstruction of the .valve 19 permitting the distribution of oil toeither or both jacks at will. Depending, upon the distance, deck and theloading point of the axle or hub,

either of riders 39, or 40, with any one of the loading cups 44, 45, 46may be used, and the adjusting screw 47 may be used with rider 40 toobtain the greatest amount of lift in each case.

The low compressed height of the beam and its relatively high extendedheight make it possible to raise the wheels of most aircrafts for easyand speedy wheel or 0 68 is provided for the purpose of permitting thefingers Patented Nov. 22, 1955 having a firm hold on the grip axle, tolift that end of the jack assembly in an upwards motion until the pairof wheels 28 on the opposite end of the jack assembly are in contactwith the ground or other supporting surface, and both jack bases 11 areentirely clear of the ground or said supporting surface. The operatorcan now move the jack assembly to any desired location, simply bypushing or pulling, since the one end of the jack assembly is supportedby the pair of wheels 28 at one end and the other end is supported bythe firm grip of the operators hand on the axle 27.

The operator can lift either end of the jack assembly thus permittingthe placing of the jack under either the right or left hand landing gearof an aircraft from the forward end of the aircraft, and have thelifting beam 36 of the jack assembly next to the aircraft wheel. Uponlowering of the jack off of the wheels, bases 11 provide a substantiallyimmovable or fixed supporting means.

It should be understood, of course, that the foregoing disclosurerelates to only a preferred embodiment of the invention and thatnumerous modifications or alternations may be made therein withoutdeparting from the spirit and the scope of the invention as set forth inthe appended claims.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

What is claimed is:

l. A readily portable hydraulic lifting assembly having a low height anda high lift comprising a pair of hydraulic jacks rigidly securedtogether in spaced relation by a single straight bar; a base positionedon the lower surface of each'of said jacks; a single hydraulic pumpmounted on said bar and operatively connected to each of said jacks; aload transmitting cap surmounting each of said jacks; and a single loadreceiving beam extending between said caps and rigidly secured thereto.

2. A readily portable hydraulic lifting assembly comprising a pair ofhydraulic jacks in spaced relation; a base attached to the lower surfaceof each of said jacks; a single stragiht bar extending between andrigidly secured to said bases at points spaced above the lower surfacesthereof; a single hydraulic pump mounted on said bar and operativelyconnected to each of said jacks; a load transmitting cap surmountingeach of said jacks; and a single load receiving beam extending betweensaid caps and rigidly secured thereto.

3. A manually portable lifting assembly comprising a pair of hydraulicjacks in spaced relation; a base positioned on the lower surface of eachof said jacks; a single straight bar extending between and rigidlysecured to said bases at points spaced above the lower surfaces thereof;means for operating said jacks mounted on said bar and operativelyconnected to each of the jacks, said 4 means comprising a single pump, ahydraulic fluid supply and a single valve for simultaneously controllingthe amount of fluid flow to each'jack; a load transmitting capsurmounting each of said jacks; a single load receiving beam extendingbetween said caps and rigidly secured thereto. v

4. A manually portable lifting assembly comprising a pair of hydraulicjacks in spaced relation; a base positioned on the lower surface of eachof said jacks; a single straight bar extending between and rigidlysecuredto said bases at points spaced above the lower surfaces thereof;means for operating said jacks mounted on said bar and operativelyconnected to each of said jacks; a load transmitting cap removablyfitted over each of said jacks; a single load receiving beam extendingbetween said caps and rigidly secured thereto; a series of loading pointreceiving means of graduated heights movably mounted on said beam.

5. A manually portable hydraulic lifting assembly comprising a pair ofhydraulic jacks in spaced relation, each of said jacks having a curvedload bearing surface; a base positioned on the lower surface of each ofsaid jacks; a single straight bar extending between and rigidly securedto said bases at points spaced above the lower surfaces thereof; meansfor operating said jacks mounted on said bar and operatively connectedto each of the jacks; a load transmitting cap removably fitted over eachof said jacks, the lower bearing face of each cap resting on the curvedload bearing surface of the jack and having a matching configuration;and a single load receiving beam extending between said caps and rigidlysecured thereto.

6. A manually portable lifting assembly comprising a pair of hydraulicjacks in spaced relation; a base positioned on the lower surface of eachof said jacks; a single straight bar extending between and rigidlysecured to said bases at points spaced above the lower surfaces thereof;means for operating said jacks mounted on said bar and operativelyconnected to each of the jacks; and a load transmitting cap removablyfitted over each of said jacks; a single load receiving beam extendingbetween said caps andrigidly secured thereto.

References Cited in the file of this patent UNITED STATES PATENTS1,994,942 Calkins Mar. 19, 1935 2,208,221 McCullough July 16, 19402,545,403 Wrenn Mar. 13, 1951 2,614,800 Garlinger et a1 Oct. 21, 19522,636,715 Gritfin Apr. 28, 1953 FOREIGN PATENTS 7,432 Great Britain 1889802,202 France June 6, 1936

